D. Rantzer et al., WEANING OF PIGS RAISED IN SOW-CONTROLLED AND IN CONVENTIONAL HOUSING SYSTEMS .1. DESCRIPTION OF SYSTEMS, PRODUCTION, AND BACTERIOLOGY, Swedish Journal of Agricultural Research, 25(1), 1995, pp. 37-46
An alternative weaning system (sow-controlled, SC) where the sow could
leave the lactation pen for a common sow pen, but the pigs could not,
was studied and compared to a conventional system (CONV) where each p
en housed a sow and her litter. The trial period began one week after
farrowing when each system received 4 sows and litters, and stopped 4
weeks after weaning. Pigs had access to creep feed and were weaned at
5 weeks of age. Twenty-two SC and 23 CONV litters were studied. Before
weaning, the SC pigs had a significantly poorer daily gain and higher
consumption of creep feed. After weaning, no significant differences
in daily gain or feed consumption were found, but the SC pigs tended t
o have a poorer feed conversion. The blood plasma levels of immunoreac
tive cationic trypsin (IRCT), an indicator of pancreas function and de
velopment, began to increase at 3 weeks of age, and continued to rise
during the trial period. The CONV pigs had a greater increase during t
he suckling period, in spite of eating less creep feed. Some SC pigs s
howed a dominance of haemolytic E. coli in rectal swabs at weaning, in
dicating that weaning may already have begun. A high proportion of hae
molytic E. coli did not always induce post-weaning diarrhoea (PWD). In
general, the incidence of PWD was low. The stockpersons considered th
e SC system to be more difficult to manage because of the larger area
to be cleaned and because the pigs occasionally managed to get out of
their pens.